D900 Code And Using A Lot Of Fuel.

[blue flash]

Hi guys, my car gone heavy on fuel. it seams to be really quite heavy not only when it's cold but even after a 100 mile trip,the temp gauge can take 15 to 20 miles to move.120 mile trip yesterday on the motorway averaging 60,65 mph and i'm using the best part of 4 gallons, its a 1.8 diesel (2005) 5 speed box...only had a service 6 thousand miles ago.oil,fuel filters, engine oil and air filter.I have done the stalk trick and can only find a D900 code. Any help would be great full. Cheers..

[salsheikh]

don't rely on the stalk trick: http://www.fordownersclub.com/forums/topic/48644-engine-systems-fault-and-dtc-d900/

[mintalkin]

with the temp guage not moving it could be a thermostat problem allowing the car to run cooler than normal, which could also be the answer to the heavy fuel usage as the car will use more fuel when cold.

[iantt]

Shouldnt take that long to warm up, sounds like thermostat jammed open,

[blue flash]

Cheers lads,would it still be the thermostat when the engine has warmed up though.